{"title":"Failure of ceramic THR with liner dislocation--a case report.","authors":"Kengo Yamamoto, Takaaki Shishido, Toshiyuki Tateiwa, Yoichi Katori, Toshinori Masaoka, Atsuhiro Imakiire, Ian Clarke","doi":"10.1080/00016470410001312-1","DOIUrl":null,"url":null,"abstract":"In September 1998, an all-alumina total hip replacement was performed in a 57-year-old woman using an ABS Cup System THR (Kyocera Ltd. Kyoto, Japan) (ABS HA Shell (CH 46)/ABS Liner (28-46)/Ball Head (28N: -4)/Perfi x Stem #12-M) for left traumatic femoral head necrosis (Figure 1a). The liner had an alumina inlay packed with polyethylene.In May 2002 discomfort appeared in the hip, with crepitation when walking. 3 weeks later, dis-location of the liner was confi rmed on radiographs. The liner had rotated about 90° in the metal shell and the ball head had been displaced in superolat-eral direction (Figure 1b). At the revision opera-tion, we observed pale gray color contamination in the synovia surrounding the neck and pseudocap-sule. The inlay had been dislocated in the liner and the stem neck had been impinged against the rim of the inlay. The ball head was in contact with the metal shell in the superolateral area. We found no distraction of ceramic parts. The liner, metal shell and alumina ball were revised into a polyethylene liner, metal shell and metal ball (Figure 1c).For the revised implant, we confi rmed the lesion and degree of injury of the implants by the naked eye and light microscopy, and observed the wear pattern of the ball head and the inlay. We used scanning electron microscopy (SEM) to examine the microstructure of the bearing surface. Based on macroscopic observation, about two-thirds of the circumference of the marginal part of the liner polyethylene had suffered a loss around the notch, to lock the liner between the shell. Metal contamination was observed on the rim of the alu-mina inlay, which had been dislocated in the liner (Figure 2).The SEM fi ndings in the normal load-bearing area suggested a very low wear rate, because the machine marks had just been smoothed out (grade II) (Shishido et al. 2002). On the other hand, in the rim of the bearing surface of the inlay and in the peripheral area of the ball head, the grain of the surface had been pulled out (grade V), so the wear was considered to be more severe (Figure 3).","PeriodicalId":75403,"journal":{"name":"Acta orthopaedica Scandinavica","volume":"75 4","pages":"500-2"},"PeriodicalIF":0.0000,"publicationDate":"2004-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00016470410001312-1","citationCount":"18","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta orthopaedica Scandinavica","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1080/00016470410001312-1","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 18
Abstract
In September 1998, an all-alumina total hip replacement was performed in a 57-year-old woman using an ABS Cup System THR (Kyocera Ltd. Kyoto, Japan) (ABS HA Shell (CH 46)/ABS Liner (28-46)/Ball Head (28N: -4)/Perfi x Stem #12-M) for left traumatic femoral head necrosis (Figure 1a). The liner had an alumina inlay packed with polyethylene.In May 2002 discomfort appeared in the hip, with crepitation when walking. 3 weeks later, dis-location of the liner was confi rmed on radiographs. The liner had rotated about 90° in the metal shell and the ball head had been displaced in superolat-eral direction (Figure 1b). At the revision opera-tion, we observed pale gray color contamination in the synovia surrounding the neck and pseudocap-sule. The inlay had been dislocated in the liner and the stem neck had been impinged against the rim of the inlay. The ball head was in contact with the metal shell in the superolateral area. We found no distraction of ceramic parts. The liner, metal shell and alumina ball were revised into a polyethylene liner, metal shell and metal ball (Figure 1c).For the revised implant, we confi rmed the lesion and degree of injury of the implants by the naked eye and light microscopy, and observed the wear pattern of the ball head and the inlay. We used scanning electron microscopy (SEM) to examine the microstructure of the bearing surface. Based on macroscopic observation, about two-thirds of the circumference of the marginal part of the liner polyethylene had suffered a loss around the notch, to lock the liner between the shell. Metal contamination was observed on the rim of the alu-mina inlay, which had been dislocated in the liner (Figure 2).The SEM fi ndings in the normal load-bearing area suggested a very low wear rate, because the machine marks had just been smoothed out (grade II) (Shishido et al. 2002). On the other hand, in the rim of the bearing surface of the inlay and in the peripheral area of the ball head, the grain of the surface had been pulled out (grade V), so the wear was considered to be more severe (Figure 3).